1. Field of the Invention
This invention pertains to an improvement in or relating to an impact type printer for printing characters of the like by actuating and controlling a plurality of dot printing elements.
2. Description of the Prior Art
In dot matrix printers, characters, symbols or the like to be printed on recording paper are formed and displayed by multiple dots. In order to have these characters or symbols clear and legible, therefore, it is preferred to increase the density of multiple dots. Hence, printing portions of dot printing elements must be arranged extremely close to one another. On the other hand, since these dot printing elements are individually actuated and controlled by respective electromagnets, a space is required around each dot printing element to dispose each electromagnet to be interconnected to the dot printing element.
for the abovementioned reasons, the conventional dot matrix printer generally have a construction in which a wire is employed for each dot printing element, the end portion of the dot printig element at which the printing portion is to be disposed is arranged as close as possible to the other and each dot printing element is curved in the arcuate form and is spaced apart from the other so that the electromagnet may be disposed in that space. Accordingly, when the dot printing element is actuated by a control signal, a considerable surface pressure acts upon a guide member that restricts the dot printing element in the arcuate form and is brought into sliding contact with the dot printing element under such a state. Among others, since the guide member close to the printing portions must support altogether a group of dot printing elements within a predetermined size, accuracy of the guide member is likely to drop due to abrasion even if a material having especially high wear resistance is employed for the guide member. Moreover, because the increase in curvature of the dot printing element is restricted by possible occurrence of buckling or the like, addition of dot printing elements would result in a remarkable increase in the volume of the dot matrix printer.